The present invention relates to an improved mute assembly for percussive musical instruments, and more particularly relates to improvements in the shape of the mute element, the arrangement of the entire assembly and the movement of the entire assembly and the movement of the mute element for pressure contact with the head of the percussive instrument.
In the construction of percussive musical instruments such as drums, a batter head is disposed, in stretched state, to one open end of a cylindrical body to obtain tonal vibrations of prescribed pitchs when striken or battered, the head being in general made of animal skins or synthetic resinous films. The head is specially regarded as giving significant influence on the quality of tones generated by the percussive instruments. The percussive instrument of this type is in general accompanied with a mute assembly which adjusts the mechanical vibration of the head to change the quality of tones to be generated by the instument when battered.
One typical example of the conventional mute assembly includes a mute element given, in general, in the form of a flat pad made of felt or the like material and the mute element is adapted for pressure contact with the inner surface (undersurface) of the head. A spring member carrying the mute element at one end thereof is fixedly provided in the cavity of the instrument and repulsion of the spring member for causing the pressure contact is adjusted by turning a screw member operably related to the spring member. Being urged by the spring member, the mute element moves towards the head from its stand-by, i.e. the inoperative, position along a circular locus. Most parts of the mute assembly but the adjusting knob for the screw member are arranged within the cavity defined by the head and the body of the instrument.
The relatively thin flat shape of the conventional mute element tends to cause poor, biased and uneven contact of the mute element when pressed against the head surface, thereby lowering mute effect on the quality of tones. In order to obviate this lowering effect, the mute element may be presented against the heat at high contact pressure, i.e. with increased spring force. But, such extremely high pressure contact of the mute element with the head surface causes change in the stretch of the head itself and, accordingly, is apt to disorder the prescribed pitch of tonal vibrations.
The circular locus to be traced by the mute element moving towards the head further amplifies the above-described biased uneven contact of the mute element with the head surface as the locus crosses the head surface obliquely.
Use of the spring member which is generally made of a metallic material tends to cause resonant vibration of the spring member when the head is beaten, thereby generating undesirable noises during the play of the percussive instrument for which the above-described conventional mute assembly is used.
The most part of the conventional mute assembly are arranged within the cavity of the percussive instrument and, with this construction, the head of the instrument when striken is first deformed convex towards inside of the instrument and simultaneously pressed against the mute element. Then, the head is repulsively moved back towards the opposite direction departing from the mute element. So, the tonal vibrations generated by the striken head are enfeebled by the existence of the mute element from the start, and the mute effect is not effectively obtained when expected. In addition, presence of the entire mute assembly within the cavity of the instrument leads to relatively difficult access to them from outside thereby making attachment and detachment of the mute assembly to and from the instrument very complicated. When the head is beaten, the air prevailing in the cavity of the instrument vibrates accordingly and the cavity functions as a kind of resonator. Presence of the parts of the mute assembly within the resonant cavity hinders ideal resonant vibration of the air in the cavity. Further, such pneumatic vibrations cause corresponding vibrations of the mechanical parts of the assembly, thereby expediting undesirable loosening of such parts in the cavity.